1b.Approach (from AD-416)
We will conduct two multi-year, multi-site field experiments at ARS and PSU to evaluate the individual and combined contributions of ecologically based weed management tactics. In the first experiment, the weed suppressive effects of cereal rye mulch and soybean population will be assessed using a factorial design including several rates of each factor. The second experiment will quantify the weed suppressive effects of mixtures of cover crops by varying species composition and their relative proportions in combination with the timing of management operations. An analytical framework will be developed for determining synergistic or antagonistic interactions between multiple weed management tactics. This framework will allow us to quantify the probabilities associated with multiple tactics applied simultaneously and of multiple consecutive tactics applied in a cumulative systems approach.

3.Progress Report

The joint action of soybean density and cereal rye mulches were evaluated at BARC and Penn State. Results are summarized in the accomplishments section of the parent project. A quantitative framework was developed to evaluate interactions between multiple weed management tactics when combined into an integrated weed management program. Progress on the framework has been reported in a Ph.D. dissertation as part of this project with Penn State.
To ensure timely completion of projects and consistent protocols between locations, meetings were held throughout the year including four collaborator meetings at Penn State and four at BARC. In addition, sessions via teleconference calls and emails were conducted with collaborators to address protocol adjustments, analysis, and manuscript preparation.